Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have detected the presence of nuclear 3,5,3'-triiodothyronine (T3) receptors in primary cultures of chick embryo hepatocytes and neurons. Hepatocytes were isolated from livers of embryos of 12, 16 and 19 days by treatment with 0.2% collagenase and hyaluronidase. They were plated at a density of 3-4 x 10(5)/35-mm petri dish in Ham's F-10 medium containing fetal calf serum, tryptose phosphate, and antibiotics. Cells were used for the binding assay at Day 3 of culture. Neurons from 8-day-old embryo brains were cultured in a serum-free medium at a density of 1.2 x 10(6) cells/35-mm petri dish and used for the binding assay after 7 days of culture. Biological activity of hepatocytes was determined by measuring insulin binding, inositol phosphate formation, and 5'-monodeiodinase activity. Neurons or glial cells in culture were identified by immunostaining with anti-neurofilaments and anti-glial fibrillary acidic protein antisera. Binding assay was performed with isolated nuclei and 0.4 M NaCl nuclear extracts. With the latter preparation, the Scatchard analysis showed, in both cells, a single, high-affinity, low-capacity T3 receptor. In the hepatocytes of 12-, 16-, and 19-day-old embryos association constants (Ka) were, respectively, 0.93 +/- 0.02, 0.74 +/- 0.03, and 0.56 +/- 0.04 nM-1, whereas the maximal binding capacities (MBC) were 2.26 +/- 0.2, 2.72 +/- 0.33, and 1.83 +/- 0.19 fmol/microgram DNA (mean +/- SE, n = 3). In neurons Ka was 1.25 +/- 0.53 nM-1 and MBC 0.59 +/- 0.14 fmol/microgram DNA (n = 3). The receptor had a sedimentation coefficient of 3.4 S, an estimated Mr of 59 kDa, and the following relative affinity for thyroid hormone analogues: TRIAC greater than L-T3 greater than L-T4. These data indicate that cultured hepatocytes and neurons of chick embryo contained T3 receptors with properties similar to those described in intact tissues from this and other species. Only the MBC of neurons was 50% lower than that observed in whole brain of embryo, but was comparable to values observed in cultured neurons from other species.
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PMID:Characterization of 3,5,3'-triiodothyronine receptors in primary cultures of hepatocytes and neurons from chick embryo. 160 Dec 52

The metabolism and DNA binding of acetylaminofluorene (AAF) was investigated in human hepatocytes that were isolated from donor liver tissue by collagenase perfusion. Hepatocytes were treated with 0.01 microM pentachlorophenol (PCP), as a sulfotransferase inhibitor, to investigate the role of sulfotransferase in human bioactivation of aromatic amines. Concentrations of PCP greater than 0.1 microM resulted in cytotoxicity as noted by detachment of cells and atypical morphology. The metabolites of AAF were identified by HPLC as aminofluorene, 7-OH-AAF, 9-OH-AAF, 5-OH-AAF, N-OH-AAF, 1-OH-AAF and 3-OH-AAF. No consistent alteration in the metabolites produced occurred with PCP treatment compared to controls. PCP treatment increased total DNA binding of AAF metabolites compared with controls, suggesting that sulfotransferase does not activate AAF in human hepatocytes. Inhibition of sulfotransferase in human hepatocytes does not decrease DNA binding of AAF metabolites as noted previously with rat hepatocytes. Therefore, PCP may inhibit a detoxication pathway. This study supports N,O-acyltransferase as the critical enzyme for the formation of the major reactive metabolite in human liver.
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PMID:Inhibition of sulfotransferase in primary cultures of human hepatocytes affecting metabolism and binding of 2-acetylaminofluorene. 161 93

The exchangeability, location, and amount of the total calcium in bone cells were studied in relation to their osteoblastic activity. Cells were isolated from neonatal rat calvariae by sequential collagenase digestion and incubated with 45Ca2+ before or after various treatments. 45Ca2+, 40Ca2+, and DNA were determined on each cell sample. Long-term experiments were performed on cultured cells. The cells closest to the forming bone had the highest alkaline phosphatase activity and the highest Ca2+ content (i.e., 17 mm Ca2+/l cell water, as compared to soft tissue cells, which have 2-3 mm Ca2+/l (Borle 1981). About 50% of this Ca2+ exchanges readily with 45Ca2+ and appears to be located almost entirely in the cell membrane. Thirty-five percent exchanges only slowly with a t1/2 of 27 hours, and is located within the cell, principally in the mitochondria as seen in pyroantimonate fixed cells (Neuman et al. 1985). In spite of its slow exchange-ability, this Ca2+ fraction can be mobilized or augmented rapidly when Ca2+ supply is reduced or increased in vitro or in vivo. 1,25(OH)2D3 given in vivo increased this intracellular Ca2+ when the Ca2+ supply was low and released it when the Ca2+ supply was high. About 15% of the Ca2+ in these cells was nonexchangeable. These results suggest that osteoblasts do process more Ca2+ when closer to the mineralization site. Whether this Ca2+ is en route from blood to bone or from bone to blood will require further study.
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PMID:Calcium in osteoblast-enriched bone cells. 163 67

Several studies have shown lipoprotein lipase (LPL) activity in human placenta, but the quantitative significance and cellular specificity of LPL in this organ are unknown. The objective of this report is to investigate the metabolism of very-low-density lipoprotein triglycerides (VLDL-TG) by the placenta, the role of LPL in this process, and the types of cells involved. Placental cells were obtained by enzymatic digestion (collagenase, hyaluronidase, and DNA-ase) and separated on a 40% Percoll gradient. The trophoblasts were the predominant cell type (80% to 85% pure) isolated at d = 1.033 to 1.048 and macrophages were predominant at d = 1.077 to 1.100 (greater than 95% pure), as characterized by eight immunocytochemical assays using cell protein-specific monoclonal antibodies. Macrophages represented 50% to 60% of cells isolated, and trophoblasts, 40% to 50%. LPL activity was assessed by VLDL-TG hydrolysis in primary 3- to 4-day tissue culture. In a representative experiment, LPL activity (nmol fatty acids (FA)/mg protein/24 h) was 101.3 +/- 5.3 in macrophages and 29.9 +/- 6.5 in the predominant trophoblast cell types, with approximately 20% of these amounts incorporated and reesterified. VLDL-TG hydrolysis and cell lipid uptake in both placental cell types was essentially abolished by a monoclonal anti-LPL antibody. When compared with a model of hepatocytes (Hep G2 cells), the hydrolysis of VLDL-TG was almost undetectable in these cells. In contrast, free fatty acids (FFA) uptake by Hep G2 cells was fourfold to sixfold greater than that by macrophages and trophoblasts, respectively. In conclusion, macrophages and trophoblasts are the two predominant placental cells isolated by enzymatic digestion.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Metabolism of very-low-density lipoprotein triglyceride by human placental cells: the role of lipoprotein lipase. 164 Aug 46

We present evidence that retinoic acid can down-regulate transcriptional activation by the nuclear protooncogene c-jun. All three members of the retinoic acid receptor (RAR) subfamily (RAR alpha, RAR beta, and RAR gamma) can repress transcriptional induction of the human collagenase gene or a heterologous promoter that contains the collagenase promoter AP-1-binding site. In contrast, the retinoid X receptor fails to repress Jun/AP-1 activity, demonstrating a significant difference between the two regulatory systems through which retinoids exert their transcriptional control. Analysis of RAR alpha mutants in transfection studies reveals that the DNA-binding domain is important for the inhibition of Jun/AP-1 activity, even though the RAR does not bind the collagenase AP-1 site. Rather, gel-retardation assays reveal that bacterially expressed full-length RAR alpha inhibits binding of Jun protein to target DNA. These data suggest that the RAR alpha may form a nonproductive complex with c-Jun and provides a simple mechanisms by which retinoic acid may limit cell growth and possibly malignant progression.
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PMID:Retinoic acid is a negative regulator of AP-1-responsive genes. 164 28

During continuous culture with serial passage, the human osteosarcoma cell line SaOS-2 showed a time-dependent decrease in skeletal alkaline phosphatase (ALP) activity. Because this was indicative of heterogeneity, subpopulations of SaOS-2 cells were isolated from replicate low-density cultures. The subpopulations were less heterogeneous and more stable (with respect to ALP) than the parent population. ALP specific activity in the subpopulations ranged from 0.05 to 2.3 U/mg protein, and cytochemical analyses indicated multiple steady-state levels of ALP activity per cell. The amount of ALP activity in SaOS-2 subpopulations was proportional to collagen production ([3H]proline incorporation into collagenase-digestible protein; r = .84, P less than .005), and to parathyroid hormone (PTH)-linked synthesis of cyclic adenosine monophosphate (cAMP) (r = .88, P less than .01). From these data, we inferred that ALP activity in SaOS-2 cells can provide a useful index of the osteoblastic phenotype, and that ALP activity, collagen production, and PTH-linked adenylate cyclase were coordinately regulated in these osteoblast-like osteosarcoma cells (ie, selection of subpopulations for ALP activity coselected for collagen synthesis and PTH-linked synthesis of cAMP). Further comparative studies showed that micromolar fluoride concentrations stimulated cell proliferation ([3H]thymidine incorporation into DNA) in low-ALP SaOS-2 subpopulations, but not in high-ALP cells (P less than .001), and that this differential sensitivity to fluoride was associated with an inverse correlation between fluoride-sensitive acid phosphatase and ALP activities (r = -.91, P less than .001).
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PMID:Skeletal alkaline phosphatase specific activity is an index of the osteoblastic phenotype in subpopulations of the human osteosarcoma cell line SaOS-2. 165 38

Renin gene expression in the mouse kidney and submandibular gland (SMG) are differentially regulated by cAMP. In this study, we examined the potential molecular mechanism responsible for this tissue-specific regulation. 32P end-labeled synthetic oligonucleotide containing mouse renin cAMP-responsive element (CRE) was incubated with kidney nuclear extracts from either control or cAMP-treated mice and analyzed by gel mobility shift assay. Our results demonstrated that cAMP induced a nuclear protein which complexed with the CRE oligonucleotide in a specific manner. This nuclear protein-DNA binding was competed effectively by the oligonucleotide containing human chorionic gonadotropin alpha-subunit CRE but not by the mouse renin DNA fragment from which the CRE was deleted by site-directed mutagenesis. In contrast, no DNA-protein complex formation could be detected when this [32P]CRE oligonucleotide was incubated with the SMG nuclear extract from control or cAMP-treated mice. However, CRE-binding protein complex formation was demonstrated in the SMG nuclear extract when the incubation was performed in the presence of 0.8% sodium deoxycholate and 1.2% Nonidet P-40, detergents that dissociate protein-protein complexes. Furthermore, in the absence of deoxycholate, we observed that SMG nuclear extract attenuated the binding of the kidney CRE-binding protein to mouse renin CRE in a dose-dependent manner and this inhibitory effect of SMG nuclear extract disappeared in the presence of sodium deoxycholate. This inhibitory nuclear protein in SMG is specific for CRE-binding protein since it does not affect nuclear protein binding to synthetic DNA oligonucleotides of human collagenase AP-1 and human metallothionein AP-2. Our data further suggest that inhibitory nuclear protein is present in lower quantities in other extrarenal tissues, i.e. testes, liver, brain, heart, but is not detectable in the kidney. Taken together, these results suggest that the SMG and certain extrarenal tissues contain nuclear trans-acting factor(s) that interact with CRE-binding protein, thereby interfering with its binding to mouse renin CRE. The presence of this inhibitory protein in the mouse SMG nucleus may contribute to the tissue-specific regulation of the renin gene expression by cAMP.
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PMID:Molecular mechanism of tissue-specific regulation of mouse renin gene expression by cAMP. Identification of an inhibitory protein that binds nuclear transcriptional factor. 165 39

Generalized recessive dystrophic epidermolysis bullosa (RDEB) is a severe inherited autosomal disease characterized by dermolytic blister formation. Enhanced collagenase and/or abnormal collagenase have been reported in skin from affected patients, suggesting that collagenase could be responsible for the absence of anchoring fibrils in this disorder. We used a genetic linkage approach to test the hypothesis that this disease is due to a defect in the collagenase gene in nine affected families. Analysis of amplified genomic DNA fragments of the collagenase gene by means of denaturing gradient gel electrophoresis (DGGE) allowed us to detect intragenic polymorphisms, which were subsequently characterized by direct genomic sequencing. Segregation analysis of these polymorphic sites showed exclusion of linkage between the collagenase gene and generalized RDEB phenotype in a family with consanguineous parents and three affected children. However, the possibility of linkage with the collagenase gene in the other eight families tested could not be excluded. The genetic markers described here provide a tool for investigating genetic linkage in other affected families. Overall, our results show that generalized RDEB can be caused by a defect in a gene other than the collagenase gene, and support the hypothesis that the genetic defect lies in abnormal anchoring fibril formation.
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PMID:Exclusion of linkage between the collagenase gene and generalized recessive dystrophic epidermolysis bullosa phenotype. 165 51

The protein encoded by herpesvirus saimiri transforming gene STP-C488 was identified and characterized. Antibodies were produced in rabbits by immunization with keyhole limpet hemocyanin-conjugated synthetic peptides specific for the predicted sequence of STP-C488. STP-C488-encoded protein was detected in recombinant Escherichia coli, transformed Rat-1 cells, transfected COS-1 cells, and in common marmoset T lymphocytes immortalized by herpesvirus saimiri strain 488. STP-C488 protein was sensitive to treatment by bacterial collagenase, consistent with the 18 uninterrupted collagenlike repeats predicted by the DNA sequence. The apparent molecular size of STP-C488 in sodium dodecyl sulfate (SDS)-polyacrylamide gels (20 to 22 kDa) was considerably larger than that predicted from the DNA sequence (9.9 kDa). Using indirect immunofluorescence tests and subcellular fractionation, STP-C488 was found to be membrane bound, primarily in perinuclear compartments. The 18 uninterrupted collagenlike repeats, sensitivity to collagenase, location in the cell, and anomalous migration through SDS-polyacrylamide gels suggest an unusual, membrane-associated, fibrous structure for this transforming herpesvirus oncoprotein.
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PMID:Identification and characterization of the herpesvirus saimiri oncoprotein STP-C488. 165 84

The effects of several antirheumatic drugs on the activity of degradative enzymes in normal and pathologic knee joint cartilage and on the proliferative activity of synovial tissue cells were studied. Inflammatory arthropathy was induced in rabbits by intraarticular papain administration. Elevated contents of proteoglycanase and collagenase, together with an increase in serine and cysteine proteinase inhibitors, were found in animals with papain-induced arthropathy. Inflammation also accelerated the rate of proliferation of cells present in the synovial tissue. In the treated animals, the reduction in enzyme activity, decrease in inhibitor content and decreased DNA proliferation rate were registered to a different degree. The suppression of protein synthesis by nonsteroidal antiinflammatory drugs may explain our findings. The best therapeutic results were achieved with glycosaminoglycan polysulphate (Arteparon).
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PMID:Effect of selected antirheumatic drugs on the metabolism of cartilage and synovial tissue in experimental arthropathy. 165 45


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